[c-nsp] ARP oddness

[Jay Nakamura]

Is it broadcasting because the destination is not in the FDB?
On Aug 19, 2011 4:49 PM, "Chuck Church" <chuckchurch at gmail.com> wrote:
> Anyone,
>
> Researching some issues at a remote site, seeing something I don't
> think should happen. A packet capture on this remote server using
wireshark
> and focusing in on ARP is seeing all the requests (as I'd expect), but I'm
> also seeing unicast replies that I shouldn't. The MAC address table on the
> switch I'm attached to shows only the MAC of this remote server on that
> port. There are no SPAN sessions on the switch either. The destination
> addresses aren't multicast, they're true unicast. Yet I'm seeing all these
> unicasts that aren't my mac address. Is there some function built into a
> Cisco switch that broadcasts these to make them act like gratuitous ARPs,
or
> am I really seeing something that shouldn't happen? It's on a Sup2+ 4500,
> running 12.2(25)EWA10 (I know it's ancient, vendor owns it...)
>
> Thanks,
>
> Chuck
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